During the decommissioning of a nuclear power plant, metal and mineral residues as well as combustible and incombustible wastes are produced. Of all the existing mass of a nuclear power plant (without fuel), approximately 10% has to be treated, and the rest can be routed to unrestricted recovery. The installation parts, wastes and secondary wastes to be treated can weigh between 20,000 metric tons and 50,000 metric tons, depending on the power plant. Most of these materials, approximately 70%, are either routed via direct decision measurement or via melting to unrestricted release. The rest, approximately 30%, is in part suitable for a disposal site (building materials and substances) and in part must be routed as moderately to weakly radioactive waste to a permanent repository.
In addition, steam generators can be processed as large components. In order to achieve the desired disposal goals, some components have to be treated repeatedly. It is assumed that the rate of return is approximately 20%. In general, only materials whose disposal path has been decided on are allowed to be delivered to the dismantling installation.
Various installations and methods for processing contaminated residues are known. For the surfaces of contaminated components that have radioactive contamination, EP0638516 A1 describes a method for removing lead and cadmium from phosphoric acid. This method is appropriate if a chemical or electrochemical decontamination takes place. But the phosphoric acid used for cleaning the contaminated parts has to be recycled. Independently thereof, various methods are known for treating residues, which can be used to transport, to sort or to cut up the residues into pieces.
The disadvantage of the known methods is that the treatment of the residues does not occur uncoupled from the decommissioning of the power plant, but rather occurs directly on site. As a result, an installation for processing contaminated residues can only be used for the decommissioning of a single installation and in accordance with its capacity. For these cases, the planning and coordination activities must be performed for each individual installation. Given the available space, there are limits in terms of the processing area. As a rule, optimal transport paths to the processing stations are not available. A modular organization is neither required nor possible because the planned and built installation is planned only for the actual power plant to be decommissioned. Synergies with a view to exchangeability of personnel between sites are as a rule not possible.
Therefore, the aim of the invention is to develop an installation and a method for processing contaminated residues that are permanently installed at a site provided for that purpose and are thus uncoupled from the decommissioning. The size of the individual processing stations should be able to be reduced or enlarged using a modular design principle without the transport paths interfering with each other. The decommissioning and decontamination installation should enable a minimum of radioactive waste to be produced so that a high proportion of residues can be routed to recycling.